Valve-like silencer on end of exhaust pipe



Nov. 23, 1965 E. MURRAY ETAL 3,219,144

VALVE-LIKE SILENCER ON END O F EXHAUST PIPE Filed July e. 1961 l Fig 1.

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43%@ ma M "d WL United States Patent O 3,219,144 VALVELIKE SILENCER NEND 0F EXHAUST PIIIE Ernest Murray and Kathleen Murray, Coddington,Engiand, assignors of one-half to William Marvin Pierson,

Pleasant Grove, Utah Filed .Iuly 6, 1961, Ser. No. 122,189 2 Claims.(Cl. 181-65) This invention relates to improvements in apparatus forsilencing the exhaust .systems of internal combustion and other engines.The object of the present invention is to provide apparatus which can befitted to the outlet end of an engine exhaust pipe and which willeffectively reduce the noise of the exhaust and which will automaticallyadjust itself according to the volume of the exhaust gases passingthrough the exhaust system.

According to this invention the apparatus for silencing the exhaustsystem of an engine comprises a valve member slidingly mounted on theend of the exhaust pipe and held by a spring onto a seat to close theend of the exhaust pipe when the engine is stationary and which is movedfrom its seat, against the action of the spring, by the exhaust gaseswhen the engine is Working, to allow the exhaust gases to escape, themovement of the valve from its seat depending on the volume of exhaustgases passing along the exhaust pipe at any given time. The valve ispreferably a cylindrical member closed at its outer end and slidinglymounted on the outer side of the end of the exhaust pipe, a spring beingprovided to move the inner end of the cylindrical member towards a seatprovided on the exterior of the exhaust pipe. A space of suitable sizeis provided between the inner side of the cylindrical member and theouter side of the exhaust pipe for the passage of the exhaust gases whenthe valve is opened by the exhaust gases. The cylindrical member ispreferably provided with a sound absorbing lining.

The invention will now be more particularly described with reference tothe accompanying drawings in which:

FIG. 1 is an axial longitudinal vertical section of silencing apparatusfor the exhaust systems of internal combustion and other enginesconstructed according to this invention.

FIG. 2 is a transverse cross section on the line 22 of FIG. l.

FIG. 3 is a plan View partly in section showing the valve open.

FIG. 4 is an elevation, partly in section, showing an alternative formof construction and FIG. 5 is a fragmentary side elevation of a modiedform of coupling member for attaching the valve to the end of an exhaustpipe.

Like letters indicate like parts throughout the drawings.

In one method of carrying out this invention the apparatus is formedfrom a cylindrical tube 1 of suitable length which is closed at itsouter end. The tube 1 is slidingly mounted on the end 2 of the exhaustpipe or an extension attached thereto, see FIGURE 5, and for thispurpose the outer side of the exhaust pipe or extension is formed with aplurality of longitudinal ribs 3 the outer edges of which engage withthe inner side of the liner 6 therein and hold the tube concentric withthe exhaust pipe 2. The ribs 3 are equidistantly spaced round theexhaust pipe 2 and may conveniently comprise four in number. The spaceformed between the exterior of the exhaust pipe 2 and the inner side ofthe liner provides passages 15 for the exhaust gases and the internaldiameter of the tube 1 or liner is made suitable to the cubic capacityof the engine with which it is to be used.

A coil spring 4 is connected between the end of the tube 1 and a crossmember S fixed in the exhaust pipe 2. Provision is made to adjust thetension of the Spring 4 so that its pull on the tube 1 can be adjustedby connecting the end of the spring to the end of the tube 1 by ascreweye 16. The spring 4 moves the open end of the tube 1 towards aseat which may comprise the conical end of a casing secured to theoutside of the exhaust pipe or the seat may be formed by the end of anexpansion chamber normally provided in the exhaust pipe.

The tube 1 is preferably provided with a lining 6 of suitable soundabsorbing material and the outer end of this lining 6 is drawn by thespring 4 towards a conical seat 7 which may be formed by the outer sideof an expansion chamber 8 provided in the exhaust system and as shown inFIGS. 1 to 4 or a seat 17 may be formed on a casing 9 for attachment inWell known manner to the end of an existing exhaust pipe as shown inFIG. 5 In order to prevent the tube 1 being forcibly pulled off theexhaust pipe 2 and the spring 4 strained, a check wire 10 (FIGS. 1, 2and 3) is provided which limits the movement of the tube 1 away from theseat 7.

Instead of a coil spring disposed inside the tube as described above, acoil or other form of spring or springs may be disposed outside the tubeand connected between the tube and a xed point and adapted to move thetube towards its seat. With heavy or large cubic capacity engines orexhaust systems the tube may be o-perated by a leaf spring or springswhich are also adapted to support the tube independently of the existingexhaust system.

In `an alternative construction shown in FIG. 4, the tube 1 is arrangedto slide freely in an outer casing 11 which is secured to the casing onwhich the seat 7 is formed. The tube 1 is moved towards the seat '7 by acompression spring 12 disposed between the end of the tube 1 and the end13 of the casing 11.

When the engine is stationary the spring holds the open end of the liner6 on the seat 7 provided and in this position the other end of the tube1 is a suitable distance from the end of the exhaust pipe 2. When theengine is `started the exhaust gases therefrom move the l-iner 6 awayfrom the seat 7 and the exhaust gases escape through the opening betweenthe end of the liner 6 and the seat 7 with a considerable reduction inthe noise of the exhaust. The distance the liner 6 moves away from itsseat depends on the volume of the exhaust gases at any given time sothat the amount the valve opens is automatically controlled by thevolume of the exhaust gases. The tube 1 may be composed of any suitablesound absorbing material or it may comprise a metal tube with a lining 6of sound absorbing material as shown in the drawings.

Apparatus constructed as described when attached to the exhaust pipe ofan internal combustion engine effects a considerable reduction Iin thenoise of the exhaust with a consequent reduction in the strain on thedriver of a vehicle to which it is fitted and also reduces to a minimumthe noise nuisance to the general public and Without any apparent effecton the efficient working of the engine.

What we claim is:

1. In combination, an exhaust pipe of an internal combustion engine, atubular extension therefrom, spaced longitudinal ribs on the extension,a tube with a closed end slidably carried on said ribs, and spring meansfor impelling the open end of the tube toward the exhaust pipe.

2. In combination, an exhaust pipe of an internal combustion engine, atubular extension therefrom, spaced longitudinal ribs on the extension,a tube with a closed end slidably carried on said ribs, a cross memberin the extension, and a coil spring connecting the cross member to theclosed end of the tube.

(References on following page) References Cited by the Examiner UNITEDf1 FOREIGN PATENTS 33,263 5/1924 Denmark. STATES PATENTS 361,422 7/1938Italy. Hensley 181--65 X 141,386 10/1930 Switzerland. Culp 181-65 5Feyens 131 65 X LEO SMILOW, Primary Examiner. KrStiaHSIl 18150 X C. W.ROBINSON, Examiner.

1. IN COMBINATION, AN EXHAUST PIPE OF AN INTERNAL COMBUSTION ENGINE, ATUBULAR EXTENSION THEREFROM, SPACED LONGITUDINAL RIBS ON THE EXTENSION,A TUBE WITH A CLOSED END SLIDABLY CARRIED ON SAID RIBS, AND SPRING MEANSFOR IMPELLING THE OPEN END OF THE TUBE TOWARD THE EXHAUST PIPE.